Answer:
Period of this wave, T = 0.142 seconds.
Step-by-step explanation:
The frequency of the sound wave, f = 7 Hz
We need to find the period of this wave. The time period of the wave is given by :
![T=(1)/(f)](https://img.qammunity.org/2020/formulas/physics/high-school/4gkvo9cbwtyubqfj0j1ztw08v8hhkh0bto.png)
![T=(1)/(7\ Hz)](https://img.qammunity.org/2020/formulas/physics/college/4akuvd3jvn1lravj17nu2q25xg4oqbyqdj.png)
T = 0.142 seconds
So, the period of this wave is 0.142 seconds. Hence, this is the required solution.